Before he died in 2014, Thomas Menino, a visionary urban leader who served as mayor of Boston for more than two decades, declared that we are living in "the era of the city." This has never been truer than it is today.

As the world continues to urbanize at an unprecedented rate, cities and their surrounding areas wield more power than ever. Currently over half of the world's population lives in cities, and that is expected to grow to 70 percent by 2050. In the United States, 82 percent of Americans live in metropolitan areas, an increase of 12 percent just since 2000.

Cities are rich with diversity and serve as vital hubs of innovation, culture and commerce. The world's top 10 cities by GDP, five of which are in the United States, have economies rivaling all but the 10 most prosperous countries. But while the populations, capital and political power of many cities is enormous, so are the scale and complexity of their challenges -- making insight into their leadership important.

Motivated by the belief that "the era of the city" is upon us, Boston University's Initiative on Cities, with support from Citi, recently published the findings of its 2016 Menino Survey of Mayors to understand the important challenges facing these cities' leaders. Named for the great Boston mayor, the survey gathered the perspectives of more than 100 sitting mayors from 41 states on contemporary issues through a series of one-on-one interviews conducted last summer.

The survey's findings reveal that despite remarkable societal advancements in urban centers, new and more complex problems are cropping up or increasing in severity. The environment, infrastructure, public services and household financial security are presenting challenges at a level that cities have never experienced before.

Not surprisingly, the survey found that two of the central issues in the 2016 presidential campaign - wealth inequality and the shrinking middle class -- were also of deep concern to mayors of cities throughout the country. Nearly half of those surveyed ranked poverty as their most pressing economic concern. In fact, 48 percent of mayors feel that those living in or near poverty are the most excluded group in their cities; when asked which constituency they need to do more to help, nearly a quarter named poor residents.

What is slightly more surprising is the level of agreement on the top issues regardless of mayors' party affiliation or city size. Mayors from cities big and small are highly attuned to the plight of their most vulnerable residents, and even in this polarized political climate the focus on poverty is shared by both Democratic and Republican mayors. That's also true of the benefits of diversity. While issues of economic inclusion and diversity illuminated deep divisions among the presidential candidates, the country's mayors were united in the goal of building more inclusive cities that are welcoming to all.

The Menino Survey provides a window into how our nation's mayors think, act and perceive their world. By gathering and synthesizing the priorities and challenges of our cities from the perspective of their leaders, the survey offers a roadmap of opportunities for civic innovation.

These types of innovations, often forged through public-private partnerships, enable us to tackle complex urban challenges such as poverty and economic insecurity and build more inclusive cities -- ones where residents can fulfill their potential and contribute to thriving urban economies.